It looks like you are trying to backup a network drive, and not the actual drive. That, if my memory doesn't fail me, isn't supported by ntbackup. Only local drives are. Change your selection to only backup from local drives.

I juss follow the dafaults of ntback up and goes for full backup of the server, during that it gives such errors i dont know how can i get rid of thsi error and can have sucessfull full backup. Please guid how can i proceed further with it.

Just create a new backup job and select the local drives of your server. I don't have an example server with exchange 2003 at the moment, but if I remember correctly, Exchange automatically creates a mapped drive to a share on Drive "G:" or something similar. Don't select that drive.

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